1. Field of the Invention
This invention relates to a built-in monitor apparatus such as an electronic game machine and etc., which is adapted to allow a built-in monitor unit having a rectangular picture screen to rotate in a 90-degree arc.
2. Description of the Prior Art
There is a recent trend to enlarge the size of the picture screen of an electronic game machine, for example up to 22-30 inches. On the other hand, there is a demand to minimize the casing for the electronic game machine as small as possible in view of a limited space for installing a number of the electronic game machines in a play room. It is also desirable to array the casings of the electronic game machines as close as possible to each other for effectively utilizing a limited installation space for the electronic game machines. Under these circumstances, it has become increasingly troublesome for an operator to change over the oblong picture screen of an electronic game machine from the vertically elongated state to the horizontally elongated state, and vice versa. Therefore, innovation on this point is now demanded in the art.
Conventionally the change-over of the oblong picture screen of an electronic game machine has been conducted as follows. First, the wirings of a monitor unit and fixing screws are detached from the casing thereof, and then the monitor unit is taken out of the casing of the electronic game machine. Thereafter, the monitor unit is turned to change the posture of the picture screen, i. e. from the vertically elongated state to the horizontally elongated state, and then the monitor unit is returned to the inside of the casing thereof. Finally, the fixings of wirings and fixing screws are conducted.
There has been also proposed as an alternative system a mechanism for rotating the oblong picture screen of an electronic game machine, in which the monitor unit is mounted on a rotatable disc so as to be rotated together with the disc.
However, the former mechanism in which the monitor unit is once taken out of the casing and, after effecting the change-over of the posture of the picture screen, returned to the casing is suffered from problems in that as the monitor unit becomes larger in size and heavier in weight, the more it becomes difficult to conduct the change-over operation.
The latter mechanism of rotating the monitor unit in a 90-degree arc together with the mounting disc is also suffered from problems in that in order to allow the rotation of monitor unit the area of monitor-mounting side of the casing is required to be equal to or larger in size than a square area encircled by four sides, each having a length corresponding to the diagonal line of the picture screen of the monitor unit, thereby inevitably causing an increase in size of the casing.
Accordingly, one of the object of the present invention is to provide a built-in monitor apparatus such as an electronic game machine and etc., with which the change-over of the posture of the picture screen thereof can be easily conducted, and at the same time the outer size of the casing thereof as well as the installing space thereof can be minimized as small as possible.
The object has been attained according to the present invention by providing a built-in monitor apparatus wherein an rectangular picture screen housed in a casing is adapted to be changed from a vertically elongated state to a horizontally elongated state, and vice versa; which is characterized to comprise;
a monitor unit comprising a cathode-ray tube;
a base unit comprising a frame for rotatably supporting said monitor unit, and a stretchable damper biased to be moved forward, each end of said damper being pivotally connected to a portion between said frame and said casing;
a guide roller mounted on said frame, and adapted to slide along a guide rail provided within said casing; and
a locking means for restraining the movement of said frame within a prescribed position of said casing.
The monitor unit may comprise; a cathode-ray tube; an escutcheon surrounding the periphery of the picture screen of the cathode-ray tube; a transparent door for covering the upper surface of the picture screen; a box-like upper frame sustaining and supporting the cathode-ray tube, while surrounding the outer wall of the cathode-ray tube; a plate disposed behind the upper frame and having a circular through-hole which is disposed concentrical with the axis of the cathode-ray tube; and a bracket for guiding the rotation of the cathode-ray tube, which is arranged along arc of the circular through-hole of the plate.
The base unit may comprise a monitor rotating plate having a ring-like plane, which is adapted to be engaged via the roller mechanisms with the bracket; a plurality of ball castors mounted at prescribed intervals on the upper surface of the monitor rotating plate so as to be contacted with the back surface of the plate; a pair of roller kept apart from each other for rotating the cathode-ray tube, which are mounted on the upper surface of the monitor rotating plate, and adapted to contact with the lower surface of the bracket so as to rotatably support the the bracket; a monitor rotating plate-fixing bracket for fixing the monitor rotating plate; a lower frame for supporting and securing the monitor rotating plate-fixing bracket; and a stretchable damper, whose upper portion is rotatably connected to the rear portion of the lower frame so as to support the lower frame while allowing ascending and descending movement thereof.
In the operation of converting the posture of the picture screen of the built-in monitor apparatus, the whole monitor unit is obliquely lifted to be taken out of the casing together with the base unit to such an extent that the rotational movement of the monitor unit is no more hindered by the frame of the casing, and then the whole monitor unit is rotated together with the transparent door to convert the posture of the picture screen. Since the monitor unit is rotatably supported in front of the monitor rotating plate of the base plate by means of a flat plate disposed at the rear portion of the monitor unit, as well as by a cathode-ray tube rotating bracket, the posture of the whole monitor unit can be easily converted together with the transparent door.
In this posture conversion operation, the locking mechanism is first released so as to effectively utilize the energized force of the stretchable damper so that the monitor unit can be easily moved forward along the guide rail.
After finishing the posture-conversion operation of the monitor unit, the monitor unit is descended back as a whole to the original position in the casing.